FIG. 1 depicts a schematic perspective view of a road section 1 equipped with three street luminaries 11a, 11b, 11c. The street luminaries, or candelabra, comprise a luminary post 111 and luminary head 112. Each street luminary enlightens a respective street zone 12a, 12b, 12c of the road section 1, each street zone having a length L. These enlightened street zones may be slightly overlapping in overlapping zones 13a, 13ab, 13bc, 13c. Usually as illustrated on FIG. 1, street luminaries are set back from the border 14 of the road section 1. For instance, they are erected on a pavement, on the border 14 of the road section 1. Indeed, due to the traffic, it is not possible to install the street luminaries right over the zones that need to be enlightened, as this would be too dangerous.
It is known to provide reflectors arranged in the luminary head, across the light path, in order to direct the light beam with an appropriate angle, towards the street.
Moreover, it is preferred to increase the distance between two consecutive street luminaries 11a and 11b, or 11b and 11c, in order to reduce the costs of installation and maintenance. Various reflector systems have been proposed to provide an elongate beam. Such reflector systems are quite bulky.
For street lighting, usual light sources are high intensity discharge lamps like sodium vapor lamps, fluorescent balloons or fluorescent tubes. However, these kinds of sources are quite bulky and they require a frequent and time-consuming maintenance. A consequence of bulkiness is that the luminary heads also are bulky, which may be a drawback under windy conditions.